public class T1斐波那契 {
    static long[] dp;
    static long mod = (long)1e9+7;
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        dp =new long[n+1];
        Arrays.fill(dp,-1);//数组全部赋值为-1
        dp[1]=1;dp[2]=2;
        System.out.print(dfs(n));
    }
    public static long dfs(int n) {
        if(dp[n]==-1) {
            return dp[n];
        }
        long ans=dfs(n-1)+dfs(n-2);
        ans%=mod;
        dp[n]=ans;
        return dp[n];
    }
}
